Sorry i'm too lazy to do a real page for this.
Name Enabler is a client side plugin that allows you to change your name on Source Engine 2007 games and on L4D by using name cvar (or with the advanced option tab on some mods).
Source engine 2007 : Name_Enabler_0.6.rar
Left 4 Dead : Name_Enabler_L4D_0.2.rar
Left 4 Dead 2: Name_Enabler_L4D2_0.1.rar